Suspend vs Network Traffic - blockers
gnu at toad.com
Tue Aug 12 22:04:31 EDT 2008
> > If we have multicast wakeup working, then IPv6 takes care of itself.
> Waking up on all multicast traffic would not only wake up the host on
> Neighbor Solicitation messages, but also on all other multicast
> traffic the interface was listening to before suspending (e.g. mDNS
> multicast messages).
> We probably do not want that...
The wake-on-multicast code *already* uses the existing multicast
filter, which is already set up by the Linux driver. It only wakes us
up when a multicast *that we're interested in* comes along. Just as
an awake Libertas only hands the host multicast packets *that we're
This is why IPv6 based their "arp" on multicast. It just works,
without waking up every other host on that network to receive a
broadcast that it didn't really need to see. And without adding
painful kludges to the network interface hardware/firmware.
I'm testing this with two laptops, each G1G1 MP, each joyride-2263.
Both are associated with an access point about four feet away. When I
ping6 -i eth0 ff02::1
I get pings back from both of them when they're awake. (In fact,
I get TWO pings back from the target XO, and one from the source.)
On both of them, "ethtool eth0" reports "Wake on: u".
When the target XO is suspended, and I do the same command,
then I get no pings back from the target. If I do "ethtool -s eth0 wol um"
on the target, and re-ping from the source, I get three lines (two
from the target, one from the source) for each ping, until the target
suspends; then I get some seconds of no response from the target,
then after it awakens, I get a bunch of packets back from it (that
If try to I ping ff02::5, which isn't interesting to the target, then
my &%&#$*((# flakey CTRL key goes out and won't let me type any more,
even with an external keyboard. So I can't test it. I've tried
talking to a "repair shop" to get a new keyboard, and got no response.
What it's supposed to do is to not wake up. That's what happened
last time I tested it. Somebody with two working keyboards will have
to do this test.
I didn't get to test them on msh0, which is where the original
bug report #4616 happened.
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